Analysis and elimination of errors in phase diversity wavefront sensing system

Phase diversity wavefront sensing (PDWFS), which has a simple configuration and a low cost, can be used to estimate wavefront for point source as well as extended source. However, there are various errors in its image collection and phase retrieval procedure. A numerical simulation of wavefront sensing errors caused by many factors is carried out in the case that the diversity function is defocus. These factors include the optical aberrations, focal plane position error, uncertainty of the defocus, image misalignment, image noise and so on. Approaches of eliminating or reducing these errors are given. The results show that these methods could reduce the errors effectively, and could improve the sensing accuracy greatly, which provide an important technical support for the practical applica